1. Field of the Invention
The present invention relates to a product formulation based on silicone elastomer compositions for the temporary adhesive bonding of a workpiece, intended to be sanded or polished, to a support substrate, the silicone elastomer composition being sandable or polishable after curing.
2. Description of the Related Art
For a sanding operation, workpieces must be mechanically fastened. In the case of high-price workpieces such as gemstones, optical lenses, art objects or semiconductor wafers, for example, such fastening frequently causes damage to the workpiece, or the fixing does not exhibit the desired stability. There is therefore a need for alternative methods of fixing. One possibility is to fasten the workpiece using a temporary adhesive bond. Since, during the operation of sanding or polishing, an unavoidable possibility is that the sanding device may come into contact with the adhesive as well, the adhesive as well must be sandable, since otherwise, for example, materials would fracture, or the sanding apparatus will be soiled or damaged. In addition, a good temperature stability at up to more than 300° C. is necessary, in order to withstand the friction, and hence increase in temperature, caused by the sanding or polishing. Temperature stability is necessary, moreover, since downstream processing steps on the workpiece may take place within a high temperature range. Chemical stability as well is an important property for an adhesive of this kind, such as stability toward cleaning chemicals, for example.
Furthermore, minimal release of volatile by-products, and the viscosity of the noncrosslinked silicone elastomer composition, are important in order to minimize, for example, the risk of contamination and hazard to health, and to allow suitable application to the workpiece. Furthermore, it must be possible, after sanding or polishing, for the adhesive to be removable from the workpiece easily and as far as possible without residue.